本文介绍了可调恒压式毛细管粘度计的工作原理，详尽分析了弯液面附加压强和驱动压差不稳定引起的误差及减少误差的方法。

• The Principle of adjustable capillary viscosimeter with constant pressure was introduced. De-tailed analysis was done as to the error caused by additive pressure of bending liquid surface and instability ofdriving pressure difference as well as the method to decrease the error.